The present invention relates to a system for controlling stall speed for an automatic electromagnetic clutch such as an electromagnetic powder clutch.
An automatic electromagnetic powder clutch for a vehicle engages when engine speed exceeds a stall speed for starting the vehicle. Generally, the stall speed is selected at a value lower than a speed which produces a maximum torque of the engine in order to avoid elevation of the temperature of the clutch and to smoothly start the vehicle. However, since the vehicle is not started at the maximum torque of the engine, it cannot produce sufficient power to climb a steep uphill slope.